Overview:The cloud architecture demonstration developed within PeTWIN presents an approach for contextualizing time-series data from petroleum production through an ontology-based semantic layer. The solution combines cloud-based infrastructure with domain knowledge represented by the Offshore Petroleum Production Plant Ontology (O3PO), providing a semantic connection between raw production data and the physical assets, measurements, and processes they represent. This architecture enables users and applications to access and explore time-series data in a more meaningful context, supporting interoperability and integration across heterogeneous data sources. The demonstration illustrates how a semantic, ontology-driven architecture can be incorporated into a Digital Twin environment to improve data organization, contextualization, and understanding in oil and gas production.